When a carpenter attaches two boards together, what hits the other harder, the hammer or the nail? Answer once in the terms of newton's third law, then again using your understanding of momentum.

Explain why the aperture of the spherical mirror should be small compared to the radius of curvature of the mirror.

The law of conservation of energy states that energy cannot be created or , energy can be from one substance to another. the first blank is ' destroyed ' and for the second blank is ' transferred '

Two forces produce equal torques on a door about the door hinge. the first force is applied at the midpoint of the door; the second force is applied at the doorknob. both forces are applied perpendicular to the door. which force has a greater magnitude?